How to create matrix file using save command in Matlab?

save('feature.mat','y'); while using this command, it creates variable y inside file feature.mat and all the data from variable y is store inside it. But I want to save the data from variable 'y' to directly into feature.mat file without creating another variable inside it. Now 'feature.mat'->y->data but I want to save like 'feature.mat'->data.

Please suggest what to do.